Ignitor plug



United States Patent 3,238,354 IGNITQR PLUG Arnold T. Lybrook, Lancaster, Ohio, assignor to Essex Wire (lorporation, Fort Wayne, Filth, a corporation of Michigan Filed Oct. 18, 1963, Ser. No. 317,290 Claims. (Ci. 219-270) This invention relates to electric cigar lighters and, more particularly, to electric cigar lighters of the type comprising a socket and an ignitor plug having a heating element thereon, the ignitor plug being manually removable from the socket when the heating element is properly heated to ignite tobacco.

Typically, the ignitor plug assembly includes a handle or knob at one end thereof and an insulator disk at the other end to which is affixed a stud member. Mounted on the stud member is a metallic shell or cup. A spirally wound heating coil is connected at one end to the stud member and at the other end to the metallic shell.

Manufacture of the ignitor plug is made difiicult for there is a tendency during assembly for the metallic shell to rotate with respect to the stud member due to the unwinding forces inherent in the spirally wound heating coil. This distortion of the heating coil will adversely effect the operation of the cigar lighter for maximum heat will not be concentrated upon the end of the cigar or cigarette to be lit and heat retentiveness of the heating coil is reduced. Further, the heating coil may be displaced due to the looseness therein, thereby causing damage to the insulation between adjacent turns of the heating coil and ultimately resulting in malfunction of the ignitor plug.

Further, it has been found that the heating coils of ignitor plugs are generally wound so as to define a fiat planar face. Such construction often places the cigar or cigarette to be lit in contact with the relatively cool end of the stud member rather than the face of the relatively hot heating coil, with the result that the cigar or cigarette does not light without being repositioned or takes a longer time to light than is otherwise necessary.

An object of the present invention is to provide a cigar lighter having an improved ignitor plug wherein the disadvantages and deficiencies of prior constructions are obviated.

Another object of the present invention is to provide a cigar lighter having an improved ignitor plug wherein a stud member is afiixed to an insulator disk and relative rotation between a retainer to which one end of the heating ribbon is connected and the stud member to which the other end of the heating ribbon is prevented by oneway ratchet means.

A further object of the present invention is to provide a cigar lighter having an ignitor plug which includes a heating ribbon defining a concave face exposed to the cigar or cigarette to be lit.

Yet another object of the present invention is to provide an improved ignitor plug which is economical to manufacture and which is compatible with present day cigar lighters.

These and other objects and advantages of the present invention will become hereafter more apparent when the following specification is read in conjunction with the accompanying drawing, wherein:

FIGURE 1 is a side view of a cigar lighter embodying the ignitor plug of the present invention;

FIGURE 2 is a longitudinal cross-sectional view of the ignitor plug taken generally along line 22 of FIGURE 1;

FIGURE 3 is a fragmentary exploded perspective view of a portion of the ignitor plug; and

FIGURE 4 is a front View illustrating the fabrication of the heating coil assembly.

Referring now to the drawing, wherein like numerals refer to like elements in each of the various views, it is seen that the cigar lighter 10 comprises an ignitor plug 12 which is removably supported in a socket 14. The socket 14 is adapted to be mounted on the dashboard 18 of a motor vehicle by means of a clamping sleeve 16 and is adapted to be in electrical connection with the grounded battery terminal of the motor vehicle.

As seen in FIGURE 1, there are provided on the tubu lar sheet metal housing of socket 14 bimetallic latch or contact fingers 20, which are adapted to receive the ignitor plug 12 and hold the same until the heating coil thereon is heated to a predetermined temperature. Upon attainment of such temperature, the contact fingers 20 warp outwardly and release the ignitor plug, which can then be grasped by the handle or knob 22 secured thereto, and removed from the socket 14 for use.

The ignitor plug 12 also includes a pair of shell or sleeve members 30 and 31 which are axially movable with respect to one another as will be more apparent hereinafter. Provided within sleeve 30 (FIGURE 2) is an elongated tubular body or connector 28, which is afiixed at one end to an end cap 26 by means of a plurality of lugs 29 extending from the forward end thereof and bent over to engage the front face of cap 26.

The handle or knob 22 is connected to a threaded stud 24 which is adapted to be threadedly engaged in an opening 25 in end cap 26. The end cap is preferably fabricated from an insulating material, as for example, a phenolic resin.

Operatively arranged in the chamber defined between the exterior of the tubular body 28 and the interior of the sleeve or shell 30 is -a spring 32. At one end, the spring 32 bears against the rear face of the end cap 26 and "at the other end, the spring seats within an annular wiper contact 34, which bears against an annular inwardly extending flangelike rear Wall 65 of shell 30.

Extending axially rearwardly from the rear wall 37 of the shell 30 mthr-ough an axial opening or aperture 36 therein is an elongated stud member 38. Carried on the stud member 38 in abutting relationship to the rear of wall 37 of shell 30 is an annular disc-like insulator 40 made from a suitable ceramic material.

Supported on the stud member 38 at the rear end thereof is a heating coil assembly comprising a heating ribbon 41, retainer 43 and elemental shell 48. The resistance ribbon 41, which is preferably formed from a fiat resistance wire or ribbon rectangular in cross-section, is afiixed at one end in the slot 42 in the end of stud member 38 and coiled upon itself. The free end of the heating ribbon 41 is affixed to the retainer 43. Adjacent turns of the ribbon 41 are insulated from one another by insulation 44, preferably a strip of ceramic insulating paper.

Provided between the front of ribbon 41 and the rear of retainer 43 on stud 38 is an annular disc-like insulator 45 made from ceramic paper or the like. The insulator 45 seats at the front thereof against flange 46 on stud member 68. Disposed at the front of flange 46 between the flange and elemental shell 48 and in abutting relation thereto is an insulating washer 47, preferably made from mic-a.

An important feature of the present invention is the configuration of the heat-ing coil. To facilitate lighting of a cigar or cigarette, it is desirable that the end thereof make contact with the rear face of the heating coil, which is heated to a relatively high temperature, rather than the end of the stud member 38, which is at a lower temperature level. In previous designs wherein rear face of the heating coil was planar, the cigar or cigarette generally contacted the stud member. In the present design, the ribbon 41 is wound upon the stud member and backed by the retainer 43 so as to maintain a conical configuration with the rear face of the heating coil having a concave configuration as indicated generally at 52. Thus, in use, the cigar or cigarette will generally engage the relatively hot concave surface 52 of the heating coil and will not contact the relatively cool end of the stud member 38, assuring a maximized localizing of heat and resulting in lighting of the cigar or cigarette in a relatively short time.

To maintain the desired configuration of the heating coil, the front surface of resistance ribbon 4-1 is constructed and arranged to abut washer 45, which has a radially extending central portion contacting flange 46 on stud 38 and a rearwardly extending conical surface portion contacting a correspondingly formed part on retainer 43. Thus, it is evident that the resistance ribbon 41 is in effect supported and backed by the retainer 43 in use.

Another important aspect of this invention is the provision of reverse rotation preventing means for preventing unwinding of the heating coil during assembly and thereby obviating early malfunction of the ignitor plug in use. Referring to FIGURES 2 and 3, it is seen that the novel reverse rotation preventing means 54 comprise interengaging one-way ratchet means on the retainer, elemental shell and insulator disk. A projection or lug 56 is stamped from the retainer 43 and bent so as to extend forwardly therefrom. The projection 56 on the retainer 43 extends into a recess or opening 60 defined by a projection or tab 62 extending from the elemental shell 48. The projection 62 formed on the elemental shell and extending generally forwardly therefrom engages with teeth or serrations 64 defined on the rear surface or face 66 of the insulator disk 40.

As seen most clearly in FIGURE 3, the retainer 43 comprises a generally cup-shaped central portion -68 having an opening or aperture 6? therethrough through which the stud member 38 extends. Formed adjacent an extremity of the retainer 42 and extending over an arc of approximately 65 degrees is an axially extending support member 70 to which one end of the heating coil may be suitably atfixed, as for example, by welding.

The elemental shell 48 comprises a ring-like member 72 surrounding and extending rearwardly beyond the retainer 43. An inwardly extend-ing flange-like portion 74 formed integrally with the ring-like member 72 defines therein an axial opening or aperture '75 for receiving the cup-shaped central portion 68 of retainer 43. The projection 62 of shell 4-8 is defined by a tab formed from and bent forwardly tfrom a place adjacent the opening 75.

The insulator disk 40 is provided with a non-circular opening 76, preferably hexagonal in cross-section, which opening is adapted to receive the non circular surface 78 on stud member 38. It will be apparent that the disk 40 is non-rotatably carried on stud member -38.

It is seen by reference to FIGURES 2 and 3 that a plurality of projections 80 provided on the connector 28 pass through openings 81 in wall '37 and engage in recesses 82 in the front face of the insulator, for aflixing the connector 28 to the disk 40 and for positioning the connector with respect to the insulator 40.

Referring now to FIGURE 4, there is illustrated the fabrication of the heating coil and stud assembly. Inititally, an end of the resistance ribbon 41, which has been pre-cut to a predetermined width, is affixed to the slotted end of the stud member 38. The ceramic insulator strip 44 is affixed to the heating ribbon by means of a suitable ceramic cement 83 which is applied to one side of the ribbon. Then the ceramic paper strip 44 and the heating ribbon 4-1 are wound about the stud member to form the heating coil.

The heating coil assembly is formed comprising the stud member 38, heating coil 41, the retainer 43 and elemental shell 48. The coil is secured at one end to stud 38 and at the other end to retainer 43, which is at this time rotatably supported on the stud member. The non-circular portion 78 of stud 38 is inserted into opening 76 in the disk 40. It will be apparent that there will be a tendency for the heating coil to unwind as the retainer 43 is not rigidly afiixed to stud 38. The provision of reverse rotation preventing means 54 prevents such undesirable unwinding of the heating coil. Projection 56 on retainer 43 will engage opening 60 in shell 48 and tab 60 on shell 48 will engage one of the teeth 64 on disk 40. These elements cooperate as one-way ratchet members to permit tightening of the heating coil but preventing unwinding thereof. After proper positioning of the elements, the end of the stud member 3-8 is extended through opening 36 in shell 30 and peened over as indicated at 87 to rigidly affix the components of the ignitor plug to one another.

By the present invent-ion, the problem of distortion and unwinding of the heating coil during assembly of the ignitor plug is obviated. The reverse rotation preventing means defined by the cooperating projection on the retainer, the projection on the elemental shell, and the teeth on the face of the insulator disk prevent relative rotation tending to unwind the heating coil. The adjacent turns of the heating coil remain tightly wound during assembly and thus in use the likelihood of displacement of the ceramic insulation between the adjacent turns is minimized, resulting in reduced malfunction and maintenance of the ignitor plug heating coil assembly. In addition, the unique configuration of the rear face of the heating coil reduces contact of the cigar or the like to be lit with the end of the stud member and assures maximum con tact of the cigar or the like with the concave face of the heating coil itself.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new, and desire to secure by Letters Patent of the United States is:

1. An ignitor plug for a cigar lighter comprising, in combination, an insulator block; a stud adapted to be aflixed to said insulator block; a metal sleeve insulatingly supported on said stud adjacent said insulator block; a retainer supported on said stud adjacent said metal sleeve; and a heating element comprising a resistance ribbon wound in a spiral coil and connected at one end to said stud and at the other end to said retainer, adjacent turns of said spiral coil being electrically insulated from one another, said retainer being rotatable on said stud for tightening said spiral coil, and cooperating means on said retainer, said sleeve, and said insulator block defining means for preventing rotation between said retainer, said sleeve, and said insulator block in a direction to on wind said resistance ribbon.

2. In a cigar lighter, an ignitor plug comprising a tubular sleeve member, an insulator disk mounted within said sleeve member, a heating element comprising a spiral coil of resistance ribbon, one end of said ribbon being secured to a supporting stud and the other end of said ribbon being secured to a retainer, a spiral coil of insulating ribbon substantially coextensive with said resistance ribbon for electrically insulating adjacent turns of said resistance ribbon, a shell disposed adjacent to said retainer, said shell and said retainer having cooperating means for operatively connecting said shell and said retainer, said shell and said insulator disk having cooperating means thereon for operatively connecting said shell and said insulator disk, said cooperating means defining one-way ratchet means for permitting tightening of said spiral coils and maintaining adjacent turns of said spiral coil in engagement during assembly of the ignitor plug, and means for affixing said supporting stud within said sleeve member to retain said heating element in tightly wound condition in use.

3. In a cigar lighter, an ignitor plug comprising a tubular sleeve member, an insulator mounted within said sleeve member, a heating element comprising a spiral coil of resistance ribbon wound in a first direction, one end of said ribbon being secured to a supporting stud and the other end of said ribbon being secured to a retainer, a spiral coil of insulating ribbon substantially coextensive with said resistance ribbon for electrically insulating adjacent turns of said resistance ribbon, a shell disposed adjacent to said retainer, said shell and said retainer having first cooperating means for operatively connecting said shell to said retainer and preventing relative rotation therebetween, said shell and said insulator having second cooperating means thereon for preventing relative rotation therebetween, said cooperating means defining one-way ratchet means for permitting tightening of said spiral coils and maintaining adjacent turns of said spiral coil in engagement during assembly of the ignitor plug, and means for affixing said supporting stud within said sleeve member to retain said heating element in tightly wound condition in use.

4. In a cigar lighter, an ignitor plug comprising a tubular body member, knob means fixed at one end of said tubular body member, an insulator disk at the other end of said tubular body member, said insulator disk having an axial aperture therethrough, stud means disposed in said aperture and extending rearwardly therefrom, a retainer on said stud means, said retainer having a conical surface thereon, a spirally wound heating coil made from resistance ribbon affixed at one end to said stud means and at the other end to said retainer and being adapted on the front face to conform to the configuration of said conical surface of said retainer so as to form a concave rear face adapted to engage a cigar or the like to be lit, an elemental shell disposed between said insulator block and said retainer, said retainer, said elemental shell and said insulator disk having cooperating means thereon for preventing relative rotation between said members.

5. In an ignitor plug, the combination comprising a stud member, a resistance ribbon affixed at one end to said stud member and coiled thereon, adjacent turns of said resistance ribbon being electrically insulated from one another, a retainer member having a generally conical portion to which the other end of the resistance ribbon is affixed and a cup shaped portion having a central opening for receiving said stud member, an elemental shell having a central opening for receiving the cup-shaped portion of said retainer member, and an insulator disk having a non-circular opening therein for receiving said stud member, said retainer member and said elemental shell being rotatable with respect to one another and to said insulation disk during assembly, reverse rotation preventing means on said retainer member, said elemental shell, and said insulator disk for preventing unwinding of said resistance ribbon during assembly, a connector member having a rear wall with an aperture therein for receiving said stud member, means for afiixing said stud member to said rear Wall of said connector member, and handle means aflixed to said connector member for facilitating manual handling of said ignitor plug.

References Cited by the Examiner UNITED STATES PATENTS 1,778,647 10/1930 Sinko 219-266 2,694,134 11/1954 Youhouse 219-270 2,778,915 1/1957 Jorgensen 219-270 3,088,015 4/1963 Cone et al 219-267 3,127,666 4/1964 Fenn 29-15562 3,161,754 12/1964 Horwitt 219-270 3,163,924 1/1965 Schnick 29-15562 RICHARD M. WOOD, Primary Examiner. 

1. AN IGNITOR PLUG FOR A CIGAR LIGHTER COMPRISING, IN COMBINATION, AN INSULATOR BLOCK; A STUD ADAPTED TO BE AFFIXED TO SAID INSULATOR BLOCK; A METAL SLEEVE INSULATINGLY SUPPORTED ON SAID STUD ADJACENT SAID INSULATOR BLOCK; A RETAINER SUPPORTED ON SAID STUD ADJACENT SAID METAL SLEEVE; AND A HEATING ELEMENT COMPRISING A RESISTANCE RIBBON WOUND IN A SPIRAL COIL AND CONNECTED AT ONE END TO SAID STUD AND AT THE OTHER END TO SAID RETAINER, ADJACENT TURNS OF SAID SPIRAL COIL BEING ELECTRICALLY INSULATED FROM ONE ANOTHER, SAID RETAINER BEING ROTATABLE ON SAID STUD FOR TIGHTENING SAID SPIRAL COIL, AND COOPERATING MEANS ON SAID RETAINER, SAID SLEEVE, AND SAID INSULATOR BLOCK DEFINING MEANS FOR PREVENTING ROTATION BETWEEN SAID RETAINER, SAID SLEEVE, AND SAID INSULTOR BLOCK IN A DIRECTION TO UNWIND SAID RESISTANCE RIBBON. 